Driving fence posts and other posts requires considerable manual effort. Manual post drivers typically include a heavy sleeve with a closed end with appropriate handles such that an operator may slide the sleeve up and down on the post to drive it into the ground. The manual effort required to drive posts, in this or other manners, increases significantly with a large number of posts to be driven. Further, ground conditions such as rocky, dry or frozen soil can significantly increase the effort required in the labor intensive task.
To this end, implements have been developed to automate the placement of posts into the ground. Many of these implements include a mounting bracket so that the implement may be connected to a vehicle such as a tractor, a pickup truck or a skid loader. Generally, the implement draws power from the vehicle. This implement may be powered by hydraulic, electrical, or mechanical energy. For hydraulic powered post driving implements, the hydraulic energy is provided by a hydraulic pump on the vehicle. The associated hydraulic fluid reservoir on the vehicle may require adaptation to accommodate the additional hydraulic fluid required to operate the hydraulic implement or a smaller hydraulic cylinder must be used on the post driving implement. The use of a smaller implement may increase the time required to drive posts. Typically, a weight is lifted by a hydraulic cylinder and released. The weight drops under the natural force of gravity, or may be assisted in the downward direction by spring force, to strike the post and thus, drive it into the ground. The larger the cylinder employed in the implement, the larger the weight may be that is raised and dropped. Additionally, these prior art post drivers require additional time to lift the weight and thus are inefficient in driving posts.
Prior art post drivers often require external support such as outriggers. The external support limits the size of a post to be driven. Since the external supports must interface with the ground, the length of a post to be driven is limited to sizes which can fit into a post driver mounted, at least in part, on the ground.